securing-authentication

securing-authentication is a skill for Claude Code, Codex from ancoleman/ai-design-components. It costs 93 tokens per session (3,306 once invoked), scanned A, original, MIT.

A guide to adding sign-in, permissions, and protection for applications and APIs. It covers standards and tools such as OAuth, single sign-on, tokens, sessions, passkeys, and role-based access.

In plain words
What is it for?
Use it to build login and signup, secure APIs, add enterprise single sign-on, support passwordless sign-in, validate tokens, and define detailed access rules.
Why use it?
It helps prevent unauthorized users or programs from accessing accounts, data, and protected operations.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/ancoleman/ai-design-components/securing-authentication
Any agent
npx skills add ancoleman/ai-design-components --skill securing-authentication
Clone the repo
git clone --depth 1 https://github.com/ancoleman/ai-design-components

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for securing-authentication

README.md
[![agentmods](https://agentmods.dev/badge/skills/ancoleman/ai-design-components/securing-authentication.svg)](https://agentmods.dev/skills/ancoleman/ai-design-components/securing-authentication)
Your own site
<a href="https://agentmods.dev/skills/ancoleman/ai-design-components/securing-authentication"><img src="https://agentmods.dev/badge/skills/ancoleman/ai-design-components/securing-authentication.svg" alt="Measured on agentmods" height="20"></a>
Per session 93 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,306 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00093 $0.03306
Opus 5 $0.00046 $0.01653
Sonnet 5 $0.00019 $0.00661
Haiku 4.5 $0.00009 $0.00331

Measured 4d ago against content hash 10f1a64b2fe2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

securing-authentication scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/generate_jwt_keys.py, scripts/validate_oauth_config.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/securing-authentication/SKILL.md · 439 lines

How it starts

The opening of the file, as written. The whole thing — 439 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Authentication & Security

Implement modern authentication, authorization, and API security across Python, Rust, Go, and TypeScript.

When to Use This Skill

Use this skill when:

  • Building user authentication systems (login, signup, SSO)
  • Implementing authorization (roles, permissions, access control)
  • Securing APIs (JWT validation, rate limiting)
  • Adding passwordless auth (Passkeys/WebAuthn)
  • Migrating from password-based to modern auth
  • Integrating enterprise SSO (SAML, OIDC)
  • Implementing fine-grained permissions (RBAC, ABAC, ReBAC)

OAuth 2.1 Mandatory Requirements (2025 Standard)

┌─────────────────────────────────────────────────────────────┐
│           OAuth 2.1 MANDATORY REQUIREMENTS                  │
│                   (RFC 9798 - 2025)                         │
├─────────────────────────────────────────────────────────────┤
│                                                             │
│  ✅ REQUIRED (Breaking Changes from OAuth 2.0)             │
│  ├─ PKCE (Proof Key for Code Exchange) MANDATORY           │
│  │   └─ S256 method (SHA-256), minimum entropy 43 chars   │
│  ├─ Exact redirect URI matching                            │
│  │   └─ No wildcard matching, no substring matching       │
│  ├─ Authorization code flow ONLY for public clients       │
│  │   └─ All other flows require confidential client       │
│  └─ TLS 1.2+ required for all endpoints                   │
│                                                             │
│  ❌ REMOVED (No Longer Supported)                          │
│  ├─ Implicit grant (security vulnerabilities)             │
│  ├─ Resource Owner Password Credentials grant              │
│  │   └─ Use OAuth 2.0 Device Flow (RFC 8628) instead      │
│  └─ Bearer token in query parameters                       │
│      └─ Must use Authorization header or POST body        │
│                                                             │
└─────────────────────────────────────────────────────────────┘

Read the full file on GitHub · 439 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 439 lines · 93 tokens per session scan A 10f1a64b2fe2

Subscribe to this mod's changes

securing-authentication is a skill published in the GitHub repository ancoleman/ai-design-components (517 stars, last pushed 8mo ago), licensed MIT. It adds 93 tokens to every session and 3,306 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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